Pb/H2SO4 bat'ries.

[SeaMonkey]

Redriderno22,

The only Battery Analyzers I've seen capable of accurately determining Ampere/Hour capacity are those that are microcontrolled.

Although, there is probably no reason that one couldn't be built for connection to a computer via the serial port that would work as well.

They monitor discharge through a known load at about 1/10th rated capacity and build a table of timed samples of voltage and current to digitally create the discharge curve.

This is then processed into a digital readout in A/H which is displayed.

They're really handy devices, for sure! But very expensive.

I reckon that's why most of us just use a lamp, such as a headlamp, a voltmeter, an ammeter and a watch to get a ballpark.

Sorry to take so long. Yup, I did fall off the edge!

[SeaMonkey]

Palic said:

"Yesterday I charged the batteries from 10V to 12V, and noticed that one cell was clear with electrolyte and not bubbling, and the other 5 were brown and dirty. Today the charge went down to 10 V again without discharge - this batt is probably shorted !"

- - - - - - - - - - - - - - -

Yes Palic, you have a shorted cell. When a cell shorts and the battery voltage drops to 10 Volts, any attempt to charge it with a standard battery charger will result in the good cells being overcharged and gassing excessively. While on charge the battery voltage will increase to 12 Volts or more, but will decrease to 10 Volts, as you've observed, when it sits for a while.

That's what causes the electrolyte looking like red-brown muddy water. The positive plates have shed considerable Lead Dioxide into the electrolyte solution and it is being stirred up by the bubbling.

Once the bubbling is stopped, by turning off the charger, the suspended Lead Dioxide particles will settle to the plates and the bottom of the cell. Eventually, this buildup will convert to Lead Sulfate, (decreasing the strength of the Sulfuric Acid solution), which will settle into a layer at the cell bottom.

As the loss of active Lead Dioxide continues, it will in time settle onto the layer of Lead Sulfate which has accumulated and short the plates of the cell.

What Redriderno22 has suggested is a good temporary procedure which may make the battery useable again, although with reduced capacity. But, if it works, with enough capacity to get you by for a considerable amount of time.

When you replace your batteries, try to find some with fibreglass fibre/mesh cell separators which fit tightly into the spaces between the plates. These separators will effectively hold the active materials onto the plates and minimize shedding into the electrolyte solution. Then, when you desulfate your batteries, nearly all of the sulfation will be restored to active plate material.

My apologies, again, for taking so long to reply.

[SeaMonkey]

Mael said:

"It is becoming a problem to find uses for the mounting stack of batteries I've restored."

- - - - - - - - - - - - - - -

Yep, that's a nice "problem" to have Mael!

Have you considered turning your new skills into a business of restoring/rejuvenating batteries for your community?

Could turn out to be very lucrative.

Well, I'm very certain you'll find,in time, that the word will get around about your ability to "fix" batteries. Then, maybe, prospective customers will come to you seeking your service!

Keep us informed, please.

[redriderno22]

thanks seamonkey,

i found a Very accurate battery tester!

A west mountain radio CBA

it will test any size batt up to 48 volts and any AH

the only thing is that it takes so long to test large batts.

I also have a stack of batteries

hope everything is good where u are

matt

[mael]

[mael]

Someone asked some time back whether I'd made a business out of fixing batteries.

Well the answer is I haven't been successful at it.

I was quite confident someone might be interested, so I typed-up some info about what I would do, and wrote individual additional explanations for each company I went to. - And made the requisite appointments.

I went to the largest second-hand car dealer here and spoke with the boss and the #2. They thanked me for the info and I could see it wouldn't be worth it for me to be competitive with the batteries which fitted 80% of the cars they sold, which were mini-cars. The trade price for new batts was 2,500 yen. I suppose that'd be very-approximately about $25.-.

- But the larger batteries up to about 80 A/H would be possible to fix and save money for them and make money for me. With their new price being between 10,000 and 15,000 yen.

And marine batteries would be the best, and they are usually the most likely to respond to desulphating. - - But I got nothing. I fixed a battery of a diesel wagon the dealer claimed had been charged and charged but wasn't anywhere strong enough to start the engine. I did that as a demo and of course for free. It worked, but I never got any contact after that.

I went to a delivery company that has a fleet of trucks and thought they might be interested in getting me to maintain their batteries so they could get more than the normal 2 years from each battery. I'm pretty confident that with some care the batts would last at least four years. But no go there either.
... So I've just settled down to refining my techniques on batteries I've picked up at scrap heaps and I use them myself or give them away.

I'd love to make some money from fixing batts. Maybe I'll find a niche sometime???

[SeaMonkey]

Mael,

Very good to hear from you again!

A simplified Desulfator circuit that I've been having very good success with is a capacitor discharge type.

It's basically this: AC is input from the line through a 15 to 25 Watt incandescent lamp, a single diode for half wave rectification, and an electrolytic capacitor of 1000 to 2000 microfarads. The DC stored in the capacitor is discharged by means of an SCR or TRIAC rated at 40 Amperes or more, into the battery being worked upon.

I've built a relay operated triggering circuit which "fires" the SCR at varying intervals of from 5 to 30 seconds. It delivers an enormous current pulse to the battery being rejuvenated, either lead-acid or NiCd. Granted, the pulsing rate is very slow, but the very high current pulses are extremely effective.

I've used it a great deal to "blast" the dendrites in NiCd cells to clear the dendrites which short the cells after a period of years.

After each trigger of the SCR the lamp illuminates to show that the capacitor is re-charging. When the lamp extinguishes the capacitor is fully charged and will deliver the most powerful pulse.

By setting the pulse rate to trigger more rapidly, the capacitor is only partially re-charged and delivers a lower voltage/lower current pulse which is safe for AA sized NiCds.

It is a high voltage device so caution needs to be exercised when using it. It would be safest to use an isolation transformer at the input.

Regarding your experiences with auto dealers and battery shops - it is very typical. They're really not interested in any technology that would prevent them from selling lots of new batteries.

They are a good source of cheap batteries for rejuvenation though. Once your friends and neighbors get wind of what you're able to do with them by restoring them to near new condition, the word will get around gradually. As more and more people become aware of your successes they'll come to you directly with their battery problems.

It'll take some time so don't give up!

[redriderno22]

sea monkey

can you post the circut you described

thanks

[SeaMonkey]

RedRiderNo22,

Yes, I'll do that. First I'll pretty it up then scan it to Projects.

[SeaMonkey]

While awaiting approval for a Project Folder I'll post the link.

It's available

The circuit is a dangerous shock hazard if used by inexperienced personnel. Although a Bleeder Resistor is not shown across the capacitor which stores the charge, it would be a good idea to install one. A one watt 100Kohm resistor placed across the capacitor would slowly discharge it over time in order to render it harmless.

When working with such a circuit always use insulated gloves. Only make connections to any battery for rejuvenation while the capacitor is discharged and the unit is either unplugged, or an installed power switch is turned off. Best is unplugged.

To allow the capacitor to discharge while the unit is in use rejuvenating a battery, unplug power and wait until the SCR triggering relay stops pulsing.

If the SCR triggering relay continues pulsing with the unit unplugged, or turned off, the Capacitor is holding a charge that is not discharging through the intended battery, probably due to a bad connection. Wait until the triggering relay stops pulsing (it will slowly discharge the capacitor) until touching any connections.

If connections to the battery being rejuvenated are not tight and secure the high current discharge will produce a spectacular spark and explosive noise. Unplug it immediately, wait until the capacitor discharges, then make proper connection.

The Pulse Rate Adjustment potentiometer should allow continuous adjustment from about One Pulse per Second, to about One Pulse each Thirty Seconds. The slower the Pulse Rate the more powerful the discharge pulses.

If zapping shorted NiCds, set the pulse rate to the highest which will trigger the SCR and discharge the capacitor before it is fully charged. This wil be a safe current level for AAA or AA NiCds. For Zapping a C cell or a D cell, use a slower pulse rate to deliver higher current pulses. A badly shorted cell (large or many dendrites) may have to be continually pulsed for 24 or more hours to clear them. For long term pulsing it is good to have a voltmeter connected across the battery being pulsed in order to monitor voltage. A Digital Voltmeter is best. When the Voltage of the cell/battery has increased to normal full charge then it is ready for testing to see how long the charge is held while sitting unloaded.

If the cell/battery discharges in a day or two, additional pulsing is needed to restore it to full service. Keep pulsing as long as necessary to reach a condition where the rejuvenated cell/battery can sit for two months without losing significant charge.

For Lead-Acid battery desulfation, start with a rapid pulse rate. Even if the Capacitor doesn't discharge when the SCR is triggered, let it continue working. Eventually the sulfation will begin to be reversed and the battery will begin to take charge. You'll know the battery is responding well to the pulses when following each discharge the lamp illuminates and gradually dims as the capacitor is re-charging.

Exercise great caution with this type of device. With the line voltage input it cannot be made hazard free.

Unless you have experience with line voltage/high voltage seek education/training in the safe procedures from someone who has the experience; such as an Electrician/Electronics Technician/Ham Radio Operator.

[redriderno22]

[redriderno22]

the transformer is ac to dc?

thanks again

[Hybrid]

[SeaMonkey]

[redriderno22]